Between 2002-2008, the Chronic Renal Insufficiency Cohort (CRIC) Study enrolled 3,939 adults with chronic kidney disease (CKD) at 7 Clinical Centers to address overarching goals of identifying risk factors for CKD progression and clarifying the relationship between kidney dysfunction and the risks of subclinical and clinical cardiovascular events and mortality. Phase 2 of CRIC extended follow-up through April 30, 2013. This application is submitted in response to RFA-DK-12-508, Limited Competition for the Continuation of the Chronic Renal Insufficiency Cohort (CRIC) Study (U01), on behalf of the Hopkins and University of Maryland (U.MD) Clinical Center. In Phase 3, the Hopkins/U.MD center has the following specific aims: 1. To re-enroll current participants [total of ~362 (203 a Hopkins, 159 at U.MD)] 2. To enroll an additional 215 participants into Phase 3 of CRIC 3. To collect exposure and outcome data per the CRIC Phase 3 protocol 4. To maintain high levels of retention in the study 5. To investigate self-reported clinical events and obtain supporting medical records and documentation. 6. To enter data and collect/process/ship biological specimens. 7. To implement local quality assurance and quality control procedures as a means to obtain standardized, high quality measurements 8. To monitor data collection, data entry, and follow-up rates 9. To participate in governance and oversight of CRIC through study wide subcommittees and activities 10. To publish and present findings from the CRIC Study 11. To promote and support the conduct of ancillary studies in CRIC, including collaboration with the broader nephrology research community. The investigative teams at Hopkins and U.MD have vast experience in the design and implementation of rigorously conducted, influential research. During Phases 1+2, the Hopkins and U.MD Center was a high performing center that exceeded its recruitment goal; achieved high follow-up rates; and collected high quality data. Likewise, center investigators have consistently had prominent leadership roles (e.g. Co-Chairs of Recruitment and Retention, Ancillary Studies, and Publications Executive Subcommittees). In Phase 3, we remain extremely well-positioned to successfully implement the study. On a final note, we remain deeply committed to the success of CRIC and look forward to providing strong scientific leadership in this tremendously important research effort.